Elevated levels of trichloroethylene, commonly called TCE, have been found in homes' drinking wells in the township.

Drinking or breathing high levels of TCE can cause a variety of nervous system problems, liver and lung damage, abnormal heartbeat and possibly death, according to the Agency for Toxic Substances and Disease Registry.

TCE is also believed to cause cancer.

Nockamixon's contamination site is centered on homes near the intersection of Routes 611 and 412.

TCE has also been found in homes along Mountain View Drive, Park Drive, Brennan Road and Tower Road.

The highest concentration of TCE pollutants was found in wells on Tower Road, said Ragesh Patel, hazardous sites cleanup program chief at DEP.

So far, DEP scientists have tested about 40 private wells in the township.

The chemical was once a commonly used degreasing agent in a number of businesses.

It was also used by homeowners at one point to clean septic systems.

There is no public water system in the rural, Upper Bucks township. Residents and businesses must rely on private wells.

"We are still looking for a source area," said Megan Harkins, DEP project supervisor.

About two dozen residents were in attendance Thursday night.

Some locals believe the contamination likely originated from Manfred DeRewal's former chemical company, which operated in Nockamixon in the 1960s.

DeRewal recycled chemicals and metals on a 113-acre property.

Chromic acid, ammonia and other elements were dumped in unlined lagoons, which then overflowed into Rapp Creek. A court order shut down the company in 1969.

It later became the Revere Chemical superfund site, and is monitored by the federal Environmental Protection Agency.

At the meeting, one resident recalled a former high school friend who worked for DeRewal, dumping truckloads of chemical waste into streams and ditches across the Upper Bucks township.

"If they could dump thousands of gallons into a ditch, it's all in there now," he said. "It's in our water, and there's nothing you can do about it."

DEP scientists will drill six water wells, aimed at testing for TCE in various locations and aquifer levels.

Though they are trying to map out how and where the chemical is spreading, "our priority is to take care of human health," said Patel.

Homeowners whose well pollution has already been identified by the DEP have been provided with bottled water.

But that's not good enough, said Tower Road resident Joy Grieger.

"We're washing our clothes, we're washing our dishes, and we're taking our showers in this water, and we have no idea," said Grieger, whose family has been using bottled drinking water since 2009.

At high levels, TCE can be inhaled through cooking or shower steam. On Thursday, DEP officials assured residents that the levels found in Nockamixon don't pose an inhalation threat.

The state agency will consider installing carbon filtration systems in homes impacted by TCE. The carbon canisters would have to be periodically replaced to remain effective.

"They should have jumped on this a lot sooner," said Grieger. "I just don't understand why they know our well is no good but we have to wait."

The DEP has been tracking this contamination site since it was notified by Bucks County Department of Health officials in the spring of 2009.